﻿#region License

// Dimebrain TweetSharp
// (www.dimebrain.com)
// 
// The MIT License
// 
// Copyright (c) 2009 Dimebrain
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
// 

#endregion

using Dimebrain.TweetSharp.Core.Extensions;
using Dimebrain.TweetSharp.Model;

namespace Dimebrain.TweetSharp.Extensions
{
    public static class GeoExtensions
    {
        public static double Yards(this double miles)
        {
            return miles * 1760;
        }

        public static double Yards(this int miles)
        {
            return miles * 1760;
        }

        public static double Kilometres(this double miles)
        {
            return miles * 1.609344;
        }

        public static double Kilometres(this int miles)
        {
            return miles * 1.609344;
        }

        public static double Kilometers(this double miles)
        {
            return miles * 1.609344;
        }

        public static double Kilometers(this int miles)
        {
            return miles * 1.609344;
        }

        public static bool IsWithin(this GeoLocation source, double miles, GeoLocation target)
        {
            return source.MilesFrom(target) <= miles;
        }

        public static double KilometresFrom(this GeoLocation origin, GeoLocation destination)
        {
            return origin.MilesFrom(destination).Kilometres();
        }

        public static double KilometersFrom(this GeoLocation origin, GeoLocation destination)
        {
            return origin.MilesFrom(destination).Kilometres();
        }

        public static double YardsFrom(this GeoLocation origin, GeoLocation destination)
        {
            return origin.MilesFrom(destination).Yards();
        }

        public static double MilesFrom(this GeoLocation origin, GeoLocation destination)
        {
            var theta = (destination.Longitude - origin.Longitude).ToRadians();
            var target = destination.Latitude.ToRadians();
            var source = origin.Latitude.ToRadians();

            var distance = target.Sin() * source.Sin() +
                           target.Cos() * source.Cos() *
                           theta.Cos();

            distance = distance.Acos().ToDegrees();

            return distance * 60 * 1.1515; // statute miles
        }
    }
}